msm: mhi_dev: Fix client callback call sequence to update channel state

Client callback for state change notification is called after updating
state in MHI driver to avoid updating stale state to the client. Also,
the client callback list and MHI mutex initialization are moved to
mhi_dev_probe since mhi_register_state_cb, where they are used,
may be called early.

Change-Id: I53b3ac7c22aadd0613d84ee533a4a3d84ee309bb
Signed-off-by: Siva Kumar Akkireddi <sivaa@codeaurora.org>